Log loader with improved linkage arrangement

ABSTRACT

A logging machine has a boom with a log loader at its outer end. A grapple arm has a grapple and heel at opposite ends, and the end of the arm adjacent the heel is pivoted to a boom handle. A rectangular link structure includes at least a portion of the arm and handle, and also includes compression and tension links. The rectangular link structure is actuated to move the grapple and heel by a cylinder connecting the link structure with the boom handle.

United States Patent Inventor John R. Hanitz Green Bay, Wis. Appl. No. 886,207 Filed Dec. 18, 1969 Patented Dec. 28, 1971 Assignee Northwest Engineering Company A Green Bay, Wis.

LOG LOADER WITH IMPROVED LINKAGE ARRANGEMENT 5 Claims, 5 Drawing Figs.

US. Cl.. 214/147 AS Int. Cl B66c 1/44 Field of Search 214/147 Astilifiu o, 147 R [56] References Cited UNITED STATES PATENTS 3,204,795 9/1965 Larson 214/147 AS 2,754,977 7/1956 Przybylski 214/147 G X Primary Examiner-Albert J. Makay Assistant Examiner-George F. Abraham Attorney-Andrus, Sceales, Starke & Sawall PATENTEU [E028 an SHEET 1 BF 2 3H INVENTOR. JOHN RHANITZ F IG 3 Attorneys PATENIED M62819?! SHEET 2 BF 2 INVENTQR JOHN RHAN TZ Attorneys LOG LOADER WI'II-I IMPROVED LINKAGE ARRANGEMENT BACKGROUND OF THE INVENTION This invention relates to a log loader with an improved linkage arrangement.

Various devices have been developed over the years for handling logs. At least some of these machines have utilized an assembly comprising a grapple and a separate heel to grasp and level a log so that it is kept horizontal while it is being moved. In Larson U.S. Pat. No. 3,165,215, for example, the grapple and heel are mounted on an arm which is pivotally mounted intermediate its ends. In other devices, the grapple has been mounted to an arm which in turn is pivotally mounted at its other end, and the piston end of an actuating cylinder is connected directly to the arm.

SUMMARY OF THE INVENTION The present invention constitutes an improvement over prior log loaders, such as those mentioned above, and utilizes a linkage arrangement and geometry which provides substantial pulling power for the actuating cylinder.

DESCRIPTION OF THE DRAWINGS sembly;

FIG. 3 is a view of the grapple taken on line 3-3 of FIG. 2;

FIG. 3 is a view of the grapple taken on line 3-3 of FIG. 2;

FIG. 4 is a view of the heel taken on line 4-4 of FIG. 2; and

FIG. is a schematic view of the device and showing the assembly in various positions.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIGURE 1 of the drawings, the invention is utilized in connection with a mobile crawler-type logging machine having an operators cab 1 which is swingable on a turntable 2 about a vertical axis. Turntable 2 is mounted on a suitable machine chassis or frame which also supports crawler means 3 for maneuvering the machine over the terrain. A suitable boom 4 extends from the machine frame.

In accordance with the invention, a log loader assembly 5 is attached to the end of boom 4. For this purpose, an elongated boom handle 6 is pivotally attached adjacent its upper end, as at 7, to the end of boom 4. Boom handle 6 is selectively pivoted about point 7, as by a handle cylinder 8 which is connected between boom 4 and the extreme upper handle end. Cylinder 8 may be actuated in any suitable well-known manner.

Log loader assembly 5 is attached to the lower end portion of boom handle 6, and comprises an elongated grapple arm 9 which is pivotally mounted at one end to the lower end of boom handle 6, as at fixed pivot point 10. The outer end of arm 9 pivotally carries a grapple 11 having suitable jaws 12 which may be actuatable, as by cylinders 13, to grip a log. The inner end of arm 9, opposite from grapple 11, carries an armate cradle-shaped heel 14 which is removably secured to the arm, as by bolts 15. Bee] 14 is thus fixed to arm 9 for pivotal movement therewith, and is disposed below pivot point 10.

During operation of the device, assembly 5 is positioned over a log so that heel 14 is adjacent the log end and grapple 11 is disposed inwardly thereof. The assembly is then lowered to engage grapple 11 with the log, and raised to pick up the log. This raising and lowering function is provided by an actuating means, which in this case comprises a grapple arm cylinder 16, one end of which is pivotally mounted to the upper portion of boom handle 6, as at 17.

In accordance with the invention, the lower end of cylinder 16 is connected to one comer of a rectangular link structure. For this purpose, a tension link 18 extends between the lower cylinder end and an intermediate portion of grapple arm 9, and is pivotally secured thereto, as at 19 and 20 respectively. In addition, a compression link 21 extends between the lower cylinder end and boom handle 6, and is pivotally secured thereto, as at pivot points 19 and 22 respectively. Pivot point 22 is spaced generally above pivot point 10, so that the lower portion 23 of boom handle 6 forms one side of the rectangle, together with members 9, l8 and 21.

Cylinder I6 is actuated in any suitable well-known way, such as through hydraulic lines 24 and valve 25.

Arm 9 and link 21 form opposite sides of the rectangle, as do link 18 and handle portion 23. In addition, inner pivot points 10 and 22 are fixed relative to boom handle 6, while outer pivot points 19 and 20 are adapted to define arcuate paths about the respective fixed pivots during log handling. Pivot points 10 and 19 are diagonally across the rectangle, as are pivots 20 and 22.

The resultant structure provides a geometry wherein cylinder pivot point 19 never goes over center of pivot point 10 at the time of log pickup. See FIG. 5. Thus a high mechanical advantage is maintained at all times, and the moving force of cylinder 16 is translated primarily into rotational movement, rather than into compressive force against point 10.

Since the device is operated so that the center of gravity of a log is substantially beyond grapple ll, lifting of arm 9 and the grapple will cause the short end of a log to move upwardly and engage heel 14. The log may then be loaded onto a suitable vehicle for transportation to another location.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

I. In a logging machine having a boom, a log loader comprising:

a. a boom handle pivotally connected to the boom,

b. a grapple arm pivotally connected at one end to said boom handle,

c. a long grapple and heel on said grapple arm,

d. means, including at least portions of said boom handle and grapple arm, forming a rectangular link structure,

e. and actuating means connected to said structure for pivotally moving the latter to thereby raise and lower said grapple arm and heel,

f. the pivotal connection between said grapple arm and boom handle being disposed across said rectangular link structure from the connection of said actuating means thereto.

2. In a logging machine having a boom, a log loader comprising:

a. a boom handle pivotally connected to the boom,

b. a grapple arm pivotally connected at one end to said boom handle,

c. a log grapple and heel on said grapple arm,

d. means, including at least portions of said boom handle and grapple arm, forming a rectangular link structure,

e. and actuating means connected to said structure for pivotally moving the latter to thereby raise and lower said grapple arm and heel,

f. said actuating means comprising a cylinder connected at one end to said boom handle,

g. said means (d) including:

1. a tension link extending between the other end of said cylinder and said grapple arm and pivotally connected thereto,

2. and a compression link extending between the said other end of said cylinder and said boom handle and pivotally connected thereto.

3. The logging machine of claim 2 in which:

a. the pivotal connections of said grapple arm and compression link to said boom handle are fixed relative to the latter,

b. and the pivotal connections of said tension link to said cylinder and grapple arm are arcuately movable relative 5 to said boom handle.

4. The logging machine of claim 3 in which:

a. said grapple and said heel are disposed at opposite ends of said grapple arm with said heel being disposed below the pivotal connection between said arm and said boom handle,

b. and said heel is of arcuate cradle shape and is removably fixed to said grapple arm.

5. In a logging machine having a boom, a log loader comprising:

a. a boom handle pivotally connected to the boom, b. a grapple arm pivotally connected at one end to said boom handle, c. a log heel disposed at said one end of said grapple arm,

d. a log grapple disposed at the other end of said grapple arm,

e. means, including at least portions of said boom handle and grapple arm, forming a rectangular link structure,

f. and actuating means connected to said structure for pivotally moving the latter to thereby raise and lower said grapple arm and heel.

t I I! i '0' 

1. In a logging machine having a boom, a log loader comprising: a. a boom handle pivotally connected to the boom, b. a grapple arm pivotally connected at one end to said boom handle, c. a long grapple and heel on said grapple arm, d. means, including at least portions of said boom handle and grapple arm, forming a rectangular link structure, e. and actuating means connected to said structure for pivotally moving the latter to thereby raise and lower said grapple arm and heel, f. the pivotal connection between said grapple arm and boom handle being disposed across said rectangular link structure from the connection of said actuating means thereto.
 2. In a logging machine having a boom, a log loader comprising: a. a boom handle pivotally connected to the boom, b. a grapple arm pivotally connected at one end to said boom handle, c. a log grapple and heel on said grapple arm, d. means, including at least portions of said boom handle and grapple arm, forming a rectangular link structure, e. and actuating means connected to said structure for pivotally moving the latter to thereby raise and lower said grapple arm and heel, f. said actuating means comprising a cylinder connected at one end to said boom handle, g. said means (d) including:
 2. and a compression link extending between the said other end of said cylinder and said boom handle and pivotally connected thereto.
 3. The logging machine of claim 2 in which: a. the pivotal connections of said grapple arm and compression link to said boom handle are fixed relative to the latter, b. and the pivotal connections of said tension link to said cylinder and grapple arm are arcuately movable relative to said boom handle.
 4. The logging machine of claim 3 in which: a. said grapple and said heel are disposed at opposite ends of said grapple arm with said heel being disposed below the pivotal connection between said arm and said boom handle, b. and said heel is of arcuate cradle shape and is removably fixed to said grapple arm.
 5. In a logging machine having a boom, a log loader comprising: a. a boom handle pivotally connected to the boom, b. a grapple arm pivotally connected at one end to said boom handle, c. a log heel disposed at said one end of said grapple arm, d. a log grapple disposed at the other end of said grapple arm, e. means, including at least portions of said boom handle and grapple arm, forming a rectangular link structure, f. and actuating means connected to said structure for pivotally moving the latter to thereby raise and lower said grapple arm and heel. 